Lightning-arrester



(No Model.)

L. BELL.

LIGHTNING ARRESTER.

' Patented May 13, 1890.

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UNITED STATES PATENT OEEIcE.

LOUIS BELL, OF LAFAYETTE, INDIANA.

LlGHTNlNG-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 427,540, dated May 13, 1890.

Application filed November '7, 1889. Serial No. 329,534. (No model.)

To all whom it may concern: 7

Be it known that I, LOUIS BELL, of Lafayette, in the county of Tippecanoe and State of Indiana, have invented certain new and useful Improvements in Lightning-Arresters; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying draw ing, forming a part of this specification, and to the letters of reference marked thereon.

My invention relates to that class of lightning-arresters in which an impedence-coil (a coil which will impede the discharge of a static charge or sudden variations in the current, while offerin g slight resistance to the ordinary line-current) is employed in connection with slightly-separated points or surfaces, one of which is connected to the linewire and the other to earth.

The objects of the invention are to produce a practical device of simple construction which will be more efficient, and desirable than those heretofore constructed, a further object being to arrange the points or surfaces so that they will be kept constantly bright and free from dust, in order to facilitate the passage of the lightning and to provide for use in connection therewith a coil of large impedencc and small ohmic resistance.

The invention therefore consists, primarily, in locating an impedence-coil in the main circuit and locating the arr-ester points or surfaces between which is the space forming the break in the ground-wire in an exhausted chamber. I

It consists, secondly, in combining with the coil and points, as above, an automatic switch operated by the passage of electricity through the ground-wire to break a circuit of the dynamo or to interrupt the are between the arrester-points.

It consists, thirdly, in certain novel details of construction and combinations and ar rangements of parts, to be hereinafter described, and pointed out in the claims at the end of this specification.

The accompanying drawing represents a diagrammatic view of an apparatus for carrying the invention into practice.

The line-wire A is connected with the im pcdenee-coil II and thence by the wire I to the dynamo to be protected. The coil II is made in the form of a ring-magnet of circular section in order to secure large impedence with a small amount of wire and ohmic resistance. The core of II is a continuous ring of iron forming a closed magnetic circuit, and it is wound throughout its entire length with carefLilly-insulated wire.

At a a branch wire is led to the bindingpost b, and thence by the spring-clip c to the vessel B, which contains the metallic combs e e, between which is a space or air-gap. This vessel I3 is sealed air-tight by fusion or cementing and is partially exhausted. Since an electric discharge sparks more readily across a partial vaeu um, this devicewill greatly facilitate thepassage of alightning discharge, and at the same time keep the combs c e always clean and bright. The exhaustion should be so arranged with reference to the length of the air-gap that asmall increase in the potential difference between combs c 0 over that normally existing when the dynamo-electric machinery is in operation will cause a discharge across the air-gap. The vessel B is held between the spring-clip arms 0 and f, so that it may be readily removed and replaced or a new one substituted. Normally the wire a, binding-post 1), spring 0, wire (I, which passes out of B into contact with c, and comb attached to (Z are charged. If, however, lightning comes in along the line-wire A, it will be checked by the impedence-coil II and will break across the air-gap between 6 c, passing out of B to the spring f, thence to the binding-post g and the wire h,which passes first around the electro-magnet C- and thence to earth. IVhen this occurs, the current to ground thus established causes 0. to attract its armature D, pivoted at j and retained in position by pin 1', releases the trigger E, pivoted at 7. and allows the weight F, hung upon the horizontal arm of E, to fall. \Veight F is attached by cord Z to lever G, pivoted at m, and held in place by the coutact-spring n. In falling weight F swings lever G downward and breaks the contact at a.

At pivot on and bindingpost 0 wires are attached, which lead to the dynamo to be protected, so that the lever G shall form part of the shunt-circuit of said machine if shunt or compound wound, or part of the series magnetizing-coils if series-wound, so that when E falls it shall break said circuit, so that the machine shall fail to excite. This is for the purpose of saving the machine from the effects of an internal short circuit in case part of the lightning should pass to the machine and punch the insulation, and the magnetizin g-circuit being broken of course the arc established between .the combs e e is interrupted.

Having thus described my invention, what I claim as new is 1. In a 1ightning-arrester, the combination, with an exhausted vessel containing the separated points or surfaces and having external contacts leading to said points, of the connection from line to ground, having the interposed spring clips engaging said contacts, substantially as described.

2. In a lightning-arrester, the combination, with an exhausted vessel containing the separated points or surfaces and having oppositely-arranged external contacts leading to said points, of the connection from line to ground, having oppositely-arranged clips for engagement with said contacts to support the vessel, substantially as described.

3. In a lightning-arrester for induction-generators, the combination, with the main line having a ground-connection with a switchcontrolling device therein, of a shunt-circuit including the electro-magnets of the generator and a switch in said shunt-circuit controlled by the controlling device in the ground-connection, substantially as described.

4. In a lightning-arrester for shunt-wound magneto-genera tors, the combi nation,with the line-circuit, electro-magnets included in the shunt-circuit, and a switch controlling said shunt, of a ground-connection in the line-circuit and an electro-magnet in the same controlling the switch for the shunt-circuit, substantially as described.

5. In a lightning-arrester forinduction-machines, the combination, with the line having a ground-connection with a switch-controlling device therein, the electro-magnets of the generator, and an impedence-coil located in the line between the ground-connection and machine, of a switch located in the circuit for exciting said electro-magnets, operated by the switch-controlling device in the ground-coir nection, substantially as described.

6. The combination, with the slightly-separated points or surfaces of a lightning-arrester, of an exhausted vessel surrounding said points, and independent contacts connected to the points, extending through the walls of the vessel and forming contacts on the outside, substantially as described.

7. In a lightning-arrester for induction-machines, the combination, with the line having a ground-connection provided with slightlyseparated points inclosed in an exhausted vessel, a switch-controlling device interposed in said connection between the ground and separated points, and the electro-magnets of the generator, of a switch located in the circuit for exciting said electro-magnets and operated by the switch-controllin device in the ground connection, substantially as described.

8. In a lightning-arrester for shunt-wound dynamo-electric machines, the combination, with the line-circuit, electro-magn ets included in the shunt circuit, and a switch controlling said shuntcircuit, of a ground-connection for the line, a switch-controlling device therein for operating the shun t-switch, and an impedencc-coil interposed in the line between the ground-connection and machine, snbstair tially described.

' LOUIS BELL. \Vitnesses:

J os. W. WILs'rAcn, PAUL WILs'rAcn. 

